(a) Offense defined.--A person is guilty of a summary offense if he erects or maintains any device or sign in the form of railway-crossing signboards on or near any of the public highways of this Commonwealth, or if he permits such a device or sign to remain on or near the public highways of this Commonwealth, unless such sign or device is erected under a permit from the Department of Transportation, which shall approve the location, construction, and design of such sign or device.
(b) Exception.--The provisions of subsection (a) of this section shall not apply to crossing signboards erected or maintained by any railroad or railway company.